CZ169996A3 - Process of selective hydrogenation of highly saturated compounds in carbon streams - Google Patents

Abstract

A process for the selective hydrogenation of the diolefins and acetylenic compounds in an olefin-rich aliphatic hydrocarbon stream (1) comprises contacting the feed stream (1) at 40-300 DEG F under low hydrogen partial pressure of 0.1-70 psia at a total pressure of 0-350 psig in a distillation column reactor (10) containing a hydrogenation catalyst bed (12) which serves as a component of a distillation structure (10), such as supported PdO encased in a tubular wire mesh. Essentially no hydrogenation of the olefins occur. The feed stream (1) enters below or at the lower end of the catalyst bed (12), and is contacted with hydrogen fed through line (2) in the catalyst bed (12). The overhead (3) is obtained at the overhead, condensed in a condenser (20) and separated in a settler (30), and partially recycled back to catalyst bed (12) as a reflux stream (6). The bottom stream (11) is obtained at the lower end of the distillation reactor, and is partially recycled back as stream (4) after being heated in a heat exchanger (40) as recycle stream (13). Net hydrogenation effluent is obtained as stream (9), and light gases as stream (7).

Description

Process for the selective hydrogenation of highly unsaturated compounds in hydrocarbon streams

Field of technology

Ol ^ OQ

The present invention relates to the selective hydrogenation of diolefins and acetylene compounds in an olefin-rich stream. In particular, the invention relates to a process using a hydrogenation catalyst in a structure which serves both as a catalyst and as a distillation structure, for the simultaneous reaction and separation of reactants and reaction products.

This application is a continuation-in-part of USSN 07 / 933,753, filed August 24, 1992, and U.S. Pat.

Prior art

Mixed refining streams often contain a wide range of olefinic compounds. This is particularly reliable for products from either a catalytic cracking process or a thermal cracking process. These unsaturated compounds include ethylene, acetylene, propylene, propadiene, methylacetylene, butenes, butadiene, amylenes, hexenes and the like. Many of these compounds are valuable, especially as feeds for the production of chemical products. In particular, ethylene is obtained.

In addition, propylene and butenes are valuable. However, olefins having more than one double bond and acetylene compounds (containing a triple bond) are less used and are detrimental to a number of chemical processes in which a single double bond compound is used, for example in polymerization. Outside the hydrocarbon range, it is contemplated that the removal of highly unsaturated compounds is useful as feed pretreatment because such compounds are often harmful in most of the processing, storage and use of these streams.

Fractions with 4 carbon atoms are 2 sources of alkanes and alkenes for alkylation of aliphatic hydrocarbons (paraffins), for the production of motor gasoline with 8 carbon atoms by mixing the components, and as feeds for the production of ethers.

The 5 carbon refining fraction is valuable as a blender for gasoline or as a source of isoamylene for ether production by reaction with a lower alcohol. Tertiary amyl methyl ether (TAME) is fast becoming a valuable compound for refineries, due to the recent adoption of the Air Purity Act, which introduced some new restrictions on gasoline composition. Some of these requirements are

1) inclusion of a certain amount of oxidizing agents, such as tert-butyl ether, tert-amyl methyl ether or ethanol,

2) reduction of olefins in petrol and

3) reduction of vapor pressure - (volatility).

The compounds with 5 carbon atoms in the feed per unit for the production of tert-amyl methyl ether are contained in a single fraction of light naphtha, which contains any compounds with a content of 5 to 8 carbon atoms or more. This mixture can easily contain 150 to 200 compounds, making identification and separation of products difficult. Several of the minor components (diolefins) in the batch will react slowly with oxygen during storage to form a gum and other undesirable products. However, these components also react very rapidly in the process of tert-amyl methyl ether formation to form a yellow, foul-smelling gummy material. Thus, it seems desirable to remove these components either in the light naphtha fraction, which is to be used only for blending in the gasoline production itself, or as a feed to the tert-amylmethyl ether ether production process;

The use of a solid particle catalyst as part of a distillation structure in a combined distillation column reactor for various reactions is described in U.S. Patent Nos. 4,232,177, 4,307,254, 4,336,407.

504,687, 4,918,243 and 4,978,807, (dimerization) 4,242,530, (hydration) 4,982,022, (dissociation) 4,447,668 and (aromatic alkylation) 4,950,834 and 5,019,669.

-4. .3.0.2, .3.5.6. .4_44X_559 disclose catalyst structures which are suitable as distillation structures.

Hydrogenation is the reaction of hydrogen with a multiple carbon-carbon bond that is bound to a saturated compound. This reaction has long been known and is usually carried out at a pressure above atmospheric, at medium high temperatures, using a large excess of hydrogen, over a metal catalyst. The metals known to catalyze the hydrogenation reaction are platinum, rhenium, cobalt, molybdenum, nickel. , tungsten and palladium. Conventional industrial forms of catalysts use supported oxides of these metals. The oxide is reduced to the active form either before use with the reducing agent or during use with hydrogen in the batch. These metals also catalyze other reactions, especially dehydrogenation at elevated temperatures. Additionally they can promote the reaction of olefinic compounds with themselves or other olefins to produce dimers or oligomers as residence time increases _4.

Selective hydrogenation of hydrocarbon compounds has been known for quite some time. Peterson et al. in The Selective Hydrogenation of Pyrolysis Gasoline, presented by the Petroleum Division of the American Chemical Society in September 1962, discusses the selective hydrogenation of diolefins with 4 or more carbon atoms. Boítiaux et al. in Newest Hydrogenation Catalyst, Hydrocarbon Processing, March 1935, provides a general, unexplained review of the various uses of hydrogenation catalysts, including catalysts for the selective hydrogenation of propylene-rich streams and other fractions. Conventional liquid phase hydrogenations, as currently performed, require high hydrogen partial pressures, usually in excess of 1374 kPa and more often in the range up to 2748 kPa or more. In hydrogenation in the liquid phase, the partial pressure of hydrogen is essentially the pressure in the system.

* i

^of U.S. Pat. No. 2,717,202, inventor Bailey discloses

.. a countercurrent process for the hydrogenation of lard, carried out in a plurality of independent vertical chambers using a pumped catalyst under unspecified pressure conditions.

Chervenak et al. U.S. Patent No. 4,221,653 discloses co-current hydrogenation using an overflow bed at extremely high pressures. British Patent Specification No. 835,689 describes high-pressure cocurrent hydrogenation in a flowable bed, using a fraction containing compounds with 2 and 3 carbon atoms to remove acetyls. 7

Arganbright in U.S. Patent No. 5,087,780 discloses a process for the hydroisomerization of butenes using palladium oxide supported on alumina as a catalyst which is arranged in a structure used both as a catalyst and for distillation in a catalyst distillation furnace. reactor. Hydrogenation of dienes is also observed at a high hydrogen partial pressure exceeding an absolute pressure of 481 kPa, but not at an absolute pressure of about 69 kPa.

i .. the advantage of this process is that the diolefins (dienes) and acetylene compounds contained in the hydrogen stream contacted with the catalyst are converted to olefins or alkanes with very little, if any, oligomer formation or a low degree of monoolefin saturation, if it occurs at all.

The essence of the invention

The present invention includes introducing a hydrocarbon stream containing highly unsaturated compounds comprising diolefins and acetylenes, together with a hydrogen stream at an effective hydrogen absolute absolute pressure of at least about 687 Pa to less than 481 kPa, preferably less than 344 kPa, into a distillation column reactor containing hydrogenation. catalyst, which is a component of the distillation structure, and by selective hydrogenation of a portion of the highly unsaturated compounds. At hydrogen partial pressure, as defined herein, no more hydrogen is present than is necessary to keep the catalyst (most likely to reduce the catalytic metal oxide and keep it hydride) and hydrogenation of highly unsaturated compounds is used because the excess hydrogen is usually vented. Thus, preferably the partial absolute pressure of hydrogen is in the range from 687 Pa to 69 kPa and also more, but more expediently not higher than 48 kPa. Optimal results are obtained at a partial absolute pressure of hydrogen in the range from 3 to 34 kPa.

The hydrogen stream usually contains aliphatic compounds with 2 to 9 carbon atoms, which may be a narrow fraction or include only a range of said carbon content. The invention is based on the finding that the hydrogenation carried out in a catalytic distillation column requires only a part of the hydrogen partial pressure required in the liquid phase process, which is a previous industrial operation for this type of stream but gives the same or better result. Thus, the capital investment and operating costs for the present hydrogenation are substantially lower than in previous industrial operations.

Without limiting the scope of the present invention, it is proposed that the mechanism that produces the efficiency of the present process consists in condensing part of the vapor in the reaction system, with the condensation providing enough hydrogen in the condensed liquid to obtain the desired close contact between hydrogen and highly unsaturated compounds in the presence of a catalyst. , which results in the hydrogenation of these compounds.

Highly unsaturated compounds can be present in very small amounts, i.e. from a few parts per million, up to major amounts, i.e. above 90% by weight. The present invention can be used to remove impurities or to convert highly unsaturated compounds from all of the feedstock to monoolefins or alkanes as desired.

The amount of hydrogen must be adjusted to the partial pressure described so that the pressure obtained is sufficient to promote the hydrogenation reaction and to compensate for the loss of hydrogen from the catalyst, but the pressure is kept below the value which leads to hydrogenation. monoolefins, by which is meant the effective hydrogen partial pressure as used herein.

and·.

As can be seen, the amount of highly unsaturated compound in the hydrocarbon stream is a consideration to be considered in selecting the optimal hydrogen partial pressure, as at least the stoichiometric amount of hydrogen to be available for the reaction must be present in the system. If highly unsaturated compounds are impurities present in parts per million, a lower range of partial pressure and hydrogen is superfluous, but is necessary for a small number of selective reactants. Also, the nature of the gas-liquid reaction and the apparent need to introduce hydrogen into the liquid create an excess of hydrogen at partial pressures and in the preferred mode of operation.

An additional feature of the process is that some of the monoolefins that are contained in the stream or produced by the selective hydrogenation of diolefins may have more isomeric products. Isomerization can be achieved with the same group of catalysts as used in the hydrogenations. In general, the relative reaction rate for different compounds is of the order of magnitude from faster to slower as follows:

1) hydrogenation of diolefins,

2) isomerization of monoolefins a

3) hydrogenation of monoolefins.

------------- In general, se. indicates that in a stream containing diolefins, these diolefins will be hydrogenated before isomerization occurs. It has also been found that with the same excellent results, very low total overpressures can be used for optimal results in some cases of the hydrogenation according to the invention, preferably in the range from 344 to 1031 kPa.

Vyšší Satisfactory results can be used for both higher and lower pressures over a wide range.

Overview of figures in the drawings

Giant. 1 is an embodiment of this simple flow invention.

scheme one

Giant. 2 is an embodiment of this simple flow diagram of the second invention.

. Giant. 3 is an embodiment of this simple flow diagram of the invention.

the third

Giant. 4 is an embodiment of this simple flow invention.

scheme of the fourth

Detailed description and preferred embodiments

Although hydrogenation reactions are described as reversible at elevated temperatures above about 482 ° C (see, e.g., Peterson in the article cited above), under the temperature conditions used in the present invention, the hydrogenation is not reversible. In the usual use of a process where the catalyst serves as a distillation component, the equilibrium is permanently disturbed and thus the reaction shifts towards its completion, i.e. the reaction has an increased driving force because the reaction products are removed and cannot contribute to the reversible reaction (LeChatelier principle). ). In this process, which is not a drilling reaction, no advantage is obtained by removing the products from the reaction to increase the driving force of the reaction. Similarly, poor performance prior to vapor phase hydrogenations does not lead to the proposal to use distillation-type reactions. Thus, it is unexpected that catalytic distillation may be suitable for irreversible hydrogenation.

t.

The reaction catalytic distillation of the present invention is considered to be advantageous primarily because the reaction is carried out in co-current with the distillation and the initial reaction products and other components of the stream are removed from the reaction zone as quickly as possible to reduce side effects. Second, because all components are boiling, the reaction temperature is controlled by the boiling point of the mixture at system pressure. The heat from the reaction simply boils, but does not increase the temperature at a given pressure. The result is a large range of reaction rate control and product distribution can be achieved by regulating the pressure in the system. Also the adjustment of the throughput (residence time, i.e. hourly space velocity of the liquid ” ¹ ) provides further control of the product distribution and the degree of control of side reactions such as oligomerization. Another advantage that this reaction can obtain from catalytic distillation is the elution effect that the internal reflux provides to the catalyst, thereby reducing polymer formation and cracking. The internal reflux can vary from 0.2 to 20 L / D (the weight of the liquid just below the catalyst bed to the weight of the distillate) and this gives excellent results. For streams separated by sg ~ '3 ~ and ž · = 5' carbon atoms -je - usually-k-1-έ = r © grains from í - from 05do, 4 L / D.

Surprisingly, the low hydrogen partial pressure used in the distillation system does not result in the neglect of hydrogenation that would be expected from the high hydrogen partial pressure found in liquid phase systems, which is a world-wide standardized solution. Regarding the observed previous condensation phenomenon, which is a permanent factor in distillation, the same or better hydrogenation ability is expected as a result than at high pressure in the liquid phase. This means that hydrogen is introduced into the liquid so that hydrogenation takes place.

One embodiment of the present invention involves the selective hydrogenation of acetylene compounds and diolefins contained in a propylene-rich stream to purify the stream and recover larger amounts of propylene. Current rich in. propylene is fed to a distillation column reactor in a reaction distillation zone containing supported palladium oxide as a catalyst, in the form of a catalyst distillation structure. Hydrogen is supplied as necessary to promote the reaction and is believed to reduce the oxide and serve to keep it hydride. In the past, hydride status was considered active, but very small amounts of hydrogen present provide excellent results, which may indicate otherwise. In any case, the condition of the catalyst is a theoretical matter relating to a mechanism which is not the subject of the present invention. The distillation column reactor is operated at a pressure at which the reaction mixture boils in the catalyst bed. If desired, the stream of distillation residues containing any of the above boiling materials can be diverted to achieve complete separation.

When carried out with a compound containing 3 carbon atoms, using said partial pressure of hydrogen, the present invention comprises a process for the selective hydrogenation of diolefins and acetylene compounds contained in a propylene-rich stream, which comprises the following steps:

(a) implementation

1) a first stream containing propylene, diolefins and acetylene compounds and .2) a second stream containing hydrogen to the feed zone of the distillation column reactor,

b) running in this distillation column reactor

i) contacting the first and second streams in the distillation reaction zone with a hydrogenation catalyst capable of acting as a distillation structure, reacting ...

substantially all diolefins and acetylene compounds with hydrogen, to form propylene and other hydrogenated products in the reaction mixture, and ii) separating the propylene contained in the first stream and the propylene formed by reacting said diolefins. 9, and said acetylene compounds from the reaction mixture fractional #? and distillation and

c) removing the separated propylene from step b) ii) together with any other propylene and light compounds including any unreacted hydrogen from said distillation column reactor as overheads. The process may optionally comprise removing any boiling compounds with 4 or more carbon atoms from this distillation column reactor as distillation residues. There is no significant loss of propylene to hydrogenation.

In embodiments, a compound containing five carbon atoms, using the hydrogen partial pressure, the invention encompasses záyáŠ'éni ^{j-fřakce'lěhkě'} ricifty7 comprising a mixture of hydrocarbons along with a hydrogen stream to a distillation column reactor containing a hydrogenation catalyst which is a component distillation structures, and selective hydrogenation of diolefins contained in light diesel. In cocurrent, the light components, including unreacted hydrogen, are distilled and removed as the overhead fraction from the partially hydrogenated light naphtha product. In addition, and co-flowing, a portion of the C5 monoolefins is isomerized to a more desirable production process by selective hydrogenation and distillation. -amyl methyl ether ______ (TAME), which is produced by reacting an isoolefin with methanol.

Essentially all diolefins are converted to monoolefins, with very little hydrogenation of the monoolefins.

In another embodiment using light naphtha, the feed is mainly a stream of compounds with 5 carbon atoms and the light naphtha product is collected as distillation residues. The overhead fractions are passed to a condenser in which all condensable components are condensed and partially refluxed to the top of the column. In various embodiments, a reflux ratio of from 0.5 can be used. to 20: 1.

In another embodiment, utilizing light naphtha feeds and said hydrogen partial pressure, the feedstock consists of a broader stream of compounds having 5 to 8 carbon atoms. Compounds with 5 carbon atoms are separated from components containing 6 or more carbon atoms in the lower part of the distillation column reactor. Components containing compounds with 6 or more carbon atoms are removed as distillation residues, while compounds with 5 carbon atoms are boiled in the upper part of a distillation column reactor which contains a catalyst distillation structure which selectively hydrogenates diolefins. Hydrogenated compounds with 5 carbon atoms are taken as the overhead fraction together with the excess hydrogen and introduced into a condenser in which all condensable compounds are condensed and subsequently separated from non-condensable components (predominantly hydrogen), for example in a reflux drum separator. A portion of the liquid from the separators is returned to the distillation column reactor as reflux and the remainder is collected as a product which can be fed directly to the tert-amyl methyl ether production unit. If desired, an additional inert distillation section above the catalyst distillation structure can be used to laterally remove the C5 product below the excess hydrogen removal fraction along with other light compounds such as air, water and the like, which can create problems in downstream unit for the production of tert-amyl methyl ether.

In the light naphtha embodiment of the present invention, the method of selectively hydrogenating diolefins contained in light naphtha comprises the steps of:

(a) dosage

1) a first stream consisting of a light naphtha containing diolefins and

2) a second stream containing hydrogen to the feed zone of the distillation column reactor,

b) countercurrent design in this distillation column reactor

i) contacting the first and second streams in the distillation reaction zone with a hydrogenation catalyst capable of acting as a distillation structure, reacting substantially all diolefins with hydrogen to form pentenes and other hydrogenated products in the reaction mixture, and ii) controlling the pressure in the distillation column reactor so that part of the mixture is evaporated by the exothermic heat of the reaction,

c) removing part of the liquid from step b) ii) from the distillation column reactor as a distillation residue and - - = --- =

d) removing the vapors from step b) ii) together with the unreacted hydrogen from the distillation column reactor as overhead fractions.

The diolefins contained in the C5 fraction are higher boiling point than other compounds and can therefore be concentrated in the catalytic zone while the monoolefin isomer is removed from the top of the column. Interesting reactions of compounds with 5 carbon atoms are:

1) isopropene (2-methyl-1,3-butadiene) + hydrogen on

2-methyl-1-butene and 2-methyl-2-butene,

2) cis- and trans-1,3-pentadienes (cis- and trans-piperylated) + hydrogen to 1-pentene and 2-pentene,

3) 3-methyl-1-butene to 2-methyl-2-butene and 2-methyl-1-butene,

4) 2-methyl-1-butene to 2-methyl-2-butene,

5) 2-methyl-2-butene to 2-methyl-1-butene a

6) 1,3-butadiene to 1-butene and 2-butene.

The first two reactions remove unwanted components, while i

the third reaction is preferred for feed to a reactor for the production of tert-amyl methyl ether. 3-Methyl-1-butene does not react with methanol to form tert-amyl methyl ether with sulfuric acid, while both 2-methylbutenes undergo this reaction.

The present invention is carried out by a process using a column packed with a catalyst, which may contain a vapor phase and a certain amount of liquid phase, as in any distillation. The distillation column reactor is operated at a pressure at which the reaction mixture boils in a catalyst bed. The process according to the invention is carried out at an overpressure in the overhead fraction of the distillation column reactor ranging from 0 to 2405 kPa, preferably 1718 kPa or less, and at temperatures in this zone of the distillation column reactor ranging from 4 to 149 ° C, preferably from 43 to 149 ° C. 132 ° C at the required hydrogen partial pressure. Mass hourly space velocity (WHSV), which is understood here as the unit weight of the batch per hour entering the distillation column reactor per unit weight of catalyst in the catalyst distillation structures, can vary over a very wide range with other conditions, for example from 0.1 to 35 .

The advantage of using a distillation column reactor in an immediate selective hydrogenation process is better diolefin to olefin selectivity, heat retention and separation distillation, which can remove certain undesirable compounds, such as heavy sulfur contaminants, from the feed prior to exposure to the catalyst and distillation. components in the catalytic zone.

The level of foaming is preferably maintained in the catalyst bed by controlling the rate of removal of distillation residues and / or overhead, which improves the efficiency of the catalyst while reducing the need for catalyst. As can be seen, the liquid boils and the physical state is indeed accompanied by foaming, which has a higher density than would be usual in a packed distillation column, but less than a liquid without boiling vapors, as described in U.S. Patent No. 5,221,441. which is incorporated herein by reference. Essentially, by the method of foaming referred to as continuous liquid phase (LPC), it is further understood herein to mean that the flow of liquid from the catalytic distillation section is restricted so that rising steam forms a foam. The effect of the continuous phase is a liquid rather than a vapor, as is usual in distillation. The result is an increase in the contact of the liquid with the catalytic material during distillation and an improvement in the selectivity of the hydrogenation.

The temperature in the reactor is determined by the boiling point of the liquid mixture present at any given pressure? The temperature in the lower parts of the column will reflect the composition of the material in this part of the column, the temperature being higher than in the overhead fraction. At constant pressure, a change in the temperature of the system indicates a change in the composition of the material in the column. As the temperature changes, the pressure changes. The control of the temperature in the reaction zone is caused by a change in pressure, the temperature in the system increasing as the pressure increases and vice versa.

As described, the catalytic material in the hydrogenation process is in a form which serves as a feed during distillation. In a broader sense, the catalytic material is a component of the distillation system which acts both as a catalyst and as a packing in the distillation, i.e. it acts as a packing for a distillation column which has both a distillation function and also acts as a catalyst.

The reaction system can be described as heterogeneous because the catalyst remains a different entity. ^One may use any suitable hydrogenation catalysts, such as metals of Group VIII. groups of the Periodic Table of the Elements, as a basic component of the catalyst, alone or with promoters and modifiers such as palladium and gold, palladium and silver, cobalt and zirconium, nickel, preferably supported on such a support as alumina, refractory bricks, pumice, carbon , silica, resins or similar substances.

The preferred catalyst material contains palladium oxide, preferably in an amount of from 0.1 to 5.0% by weight, supported on a suitable support such as alumina, carbon ¹ or silica, for example on 3.2 mm alumina extrudates. In preferred catalytic distillation structures, particles of catalytic material are deposited on a porous plate or mesh containing a catalyst and providing surfaces for distillation, wherein the mesh is in the form of a tubular wire mesh structure or some other form of similar structure.

In one of a number of embodiments now developed in connection with this process, a preferred catalyst structure for the hydrogenation reaction of the present invention comprises a flexible, semi-rigid open tubular mesh material, such as a stainless steel wire mesh, which is filled with particles of catalytic material.

One novel catalyst structure developed for use in hydrogenation is described in U.S. Pat.

266,546, which is incorporated herein by reference in its entirety. Briefly, the novel catalyst structure is a catalyst distillation structure that includes a flexible, semi-rigid open tubular mesh material, such as a stainless steel wire mesh, filled with particles of catalytic material, the tubular material having two ends and a length ranging from about one-half. to twice the diameter of the tubular material, the first end being sealed together with the first axis to form the first flange and the second end being sealed together with the second axis to form a second flange in which the plane of the first flange in the longitudinal axis the flanges in the longitudinal direction of the axis of this tubular material form an angle of approximately 15 to 90 ° with each other.

U.S. Patent No. 4,242,530 and U.S. Patent No. 4,443,559, which are incorporated herein by reference, describe a supported catalyst for tubular structures having a plurality of pockets in a fabric web or wire mesh that is deposited in a distillation column reactor with open loops of cut stainless steel wire, joined together in the helix to be used. USSN 80/075 328, filed on June 11, 1993, which is herein referred to as & ttvaánxho component and ^ ^ state of the art, discloses = "other appropriate π'6κοϊγκ ^=" ~ structures of the prior art and provides new structures suitable for this process.

The particles of catalytic material may be powder, small irregular tufts or fragments, small beads and the like. The particulate form of the catalytic material in the structure is not critical as long as it is provided with a sufficient surface area to allow a favorable reaction rate. The catalyst particle size can best be determined for each catalyst material (because the porosity or availability of the inner surface area will vary for a different material and, of course, will affect the activity of the catalyst material).

For the hydrogenations of the present invention, the preferred catalyst structures for the feed are such that they use a more open permeable plate structure or wire mesh.

'C' ^- 'v

With reference to Fig. 1, it is now noted that the figure shows a simple flow diagram for a preferred embodiment with a compound with 5 carbon atoms. The diagram shows a distillation column reactor 10 containing a charge of a suitable hydrogenation catalyst as part of the distillation. structures 12, for example in the wire mesh arrangement described above. The column may also have a standard distillation structure 14. The light naphtha is fed via line 1 to a distillation column reactor 10 under a catalyst charge. Hydrogen is introduced as a gas through the feed line 2 into or near the bottom of the catalyst bed.

The feed containing the 5-carbon compound and hydrogen is preferably fed to the distillation column reactor separately or may be stirred before loading. The mixed mixture is introduced below the catalyst bed or at the lower end of the bed.

Hydrogen itself is fed below the catalyst beds and a stream of the C5 compound is preferably introduced below the beds. Although the hydrocarbon is preferably introduced below the bed in order to keep difficult impurities, such as sulfur compounds, out of the bed, it can be metered in up to the middle third of the bed. The pressure chosen is such that it keeps dienes and other highly unsaturated compounds in the catalyst bed while allowing propylene and lighter compounds to be distilled as the overhead fraction.

The heat is introduced into the lower part via a feed pipe 4, which is connected to the circuit via a boiler 40 and back to the column via a flow line 13. After the reaction, which is exothermic, begins, the heat of reaction causes the mixture to evaporate further in the bed. The vapors are discharged as overhead via flow line 2 and passed to condenser 20, where essentially all the condensable substances condense at a temperature of 37 ° C. . The overhead fraction is then fed to a reflux boiler 30 where the condensed material is collected and separated from non-condensable, such as unreacted hydrogen, a portion of the cooled condensed material in the reflux boiler 30 is then returned to the top of the distillation column reactor 10 through a flow tube 6. discharged via line 9, is a suitable feed for a reactor producing tert-amyl methyl ether. The non-condensable material is vented from the reflux boiler 30 through a flow tube 7 and for economic reasons hydrogen can be recycled to the reactor (not shown).

The product forming the distillation residues, which contains in particular compounds which are not diolefins having 5 carbon atoms, is discharged via the flow line 8 and can be added to motor gasoline as stable gasoline. The process is advantageous because the high heat of hydrogenation is absorbed by evaporating part of the liquid, so that temperature control is achieved by adjusting the pressure in the system. Any excess hydrogen is removed by stripping from the distillation residues produced.

In the case of 5-carbon compounds, the non-hydrogenated components are less volatile and tend to remain in the reactor for a longer period of time, which aids in the more complete course of the reaction.

Fig. 2 shows a second embodiment of the invention, in which light naphtha is fed to the column 10 above the catalyst distillation structure 12 via the feed line ¹¹ . The other arrangement is identical to Fig. 1.

---- ...... Fig. 3- illustrates the third embodiment, in which the column -.-------— ..

includes another conventional distillation structure 216 above the catalyst distillation structure 12, to separate any 4-carbon compounds and lighter materials, hydrogen, and other lower-boiling components from the 5-carbon compounds that are taken as a side stream through line 209.

Examples of embodiments of the invention

Example 1

In this example, the hydrocarbon stream is propylene-rich, such as a fraction of a 3-carbon compound from a gas production plant of a liquid phase catalytic cracking unit or a cracking stream. The usual analysis of such currents is given in Table II below.

The catalyst is 0.3% by weight of palladium oxide on 3.2 mm alumina extrudates. This hydrogenation catalyst is available from United Catalyst, Inc., under the designation G68F. Common physical and chemical properties of the catalyst, as provided by the manufacturer, are listed below.

AND

Table I

Designation

Form

Nominal size Palladium,% by weight Carrier

G68F balls

3x6 mesh (2,971 x 3,961 mm) 0.3 highly porous alumina

The catalyst is believed to be palladium hydride, which is formed during the reaction.

The hydrogen fed to the reactor must be sufficient to keep the catalyst in active form, since hydrogen is lost from the catalyst by hydrogenation. The amount of hydrogen must be adjusted by the partial pressure described so as to be sufficient to promote the hydrogenation reaction and to compensate for the loss of hydrogen from the catalyst, but to remain below the level required to hydrogenate propylene and to prevent column clogging. In general, the molar ratio of hydrogen to acetylene compounds in the feed to the reactor bed will be from about 1.05 to 2.5, preferably from 1.4 to 2.0. The presence of charged hydrogen, as described herein, does not adversely affect the physical operation of the catalytic distillation system.

Table II

Component% molar methane 0.000 ethylene 0.000 ethane 0.075 propylene 82.722 propane 11.118 methylacetylene 2.368 propadiene 1,304

Table ¹ Τι - continued

Component% molar

cyclic compounds with 3 carbon atoms 0.043 isobutane 0.000 isobytene 0.015 butene 0.242 butadiene 1,529 th most common n-butane 0.112 trans-2-butene 0.008 vinylacetylene 0.013 cis-2-butene 0.000 compounds with 5 or more carbon atoms 0.000 total 100,000 ratio of propylene to propane 7,440 th most common

The feed containing propylene and hydrogen may be introduced into the distillation column reactor separately or may be stirred prior to introduction. The metered mixture is introduced below the catalyst bed or at the lower end of the bed. Hydrogen itself is. is metered under the catalyst beds and the stream containing the 3-carbon compound is preferably metered under the beds. The hydrocarbon feed in the bed can cause certain catalysts to be deactivated by impurities. The pressure chosen is such that it keeps the dienes and acetylenes in the catalyst bed while allowing the propylene and lighter compounds to be distilled as the overhead fraction. Any unreacted hydrogen leaves as the overhead fraction with compounds with 3 carbon atoms.

The pilot plant used consists of a laboratory column with a diameter of 25.4 mm and a length of 457 cm. A 240 g catalyst of 3.2 mm alumina extrudate containing 0.3% by weight of palladium oxide was placed in wire mesh distillation bags to form the catalyst distillation structures described in U.S. Patent No. 5,266,546, which is incorporated herein by reference. includes in the prior art. The catalyst distillation structures are loaded onto a middle 305 cm column, with a lower and higher 76 cm long section with an inert distillation packing. The propylene- and hydrogen-rich feed is introduced into the column and heat is also applied to initiate the reaction. The overpressure at the head fraction is maintained between 1649 and 2164 kPa. No distillation residues are removed from the pilot plant and an equilibrium amount of compounds with 4 or more carbon atoms of about 15% by volume is present in the lower section of the column, as indicated by a constant temperature of about 60 ° C. The constant temperature also indicates that there is no formation of heavier materials as a result of any oligomerization. If any residual diene were to be detected, the temperature of the distillation residues would increase as heavier compounds were formed, indicating overall selective removal of dienes and acetylenes. In an industrial or larger unit, distillation residues would likely be involved in the separation of compounds with 4 or more carbon atoms from propylene production. Table III below shows the results of the pilot plant experiment. sř

Current introduction time, h 220 221 237. Overpressure, kPa 2164 2164 2061 Distillation temperature residues, ° C 60 60 60 Handle: Dosed amount (kg / h) (liquid) 2.72 2.72 2.72 Dosed hydrogen SCF / h (gas) 4.0 4.0 4.0 Hydrogen / acetylene ratio 1,452 th most common 1,451 th most common 1,468 th most common MA + PD in batch,% mol. 3,708 th most common 3,708 th most common 3,690 th most common ^C 3 82.3740 82.3740 82.3740 C ₃ + MA + PD 86,082 th most common 86,082 th most common 86,064 th most common dP 2.7 2.7 2.6 Head fraction analysis,% molar: Ethylene 0.065 0.020 0.080 Propylene 86,460 th most common 86,184 th most common 87,221 th most common Propane 11,717 th most common 11,304 th most common 11,074 th most common Methylacetylene 0.000 0.000 0.000 Propadien 0.000 0.000 0.000 Cyclo-C ₃ 0.049 0.054 0.045 Isobutane 0.000 0.000 0.000 Isobutene 0.014 0.016 0.010 1-Butene 0.845 1,369 th most common 0.831 n-Butene 0.127 0.207 0.117 trans-2-butene 0.544 0.950 0.472 Vinylacetylene 0.000 0.000 0.000 cis-2-butene 0.185 0.327 0.144 C ₅ and heavier 0.000 0.000 0.000 % MAPD 0.000 0.000 0.000

Table III - continued

Current introduction time, h 239 241 335 Overpressure, kPa 1924 1924 1580 Distillation temperature residues, ° C 60 60 60 Handle: Dosed amount * (kg / h) (liquid) 2.67 2.67 4.99 Dosed hydrogen SCF / h (gas). 4.0 5.0 8.0 Hydrogen / acetylene ratio 1,493 th most common 1,867 th most common 1,602 th most common MA + PD in batch,% mol. 3,690 th most common 3,690 th most common 3,690 th most common ^C 3 ^_ 82.3740 82.3740 82.3740 C ₃ + MA + PD 86,064 th most common 86,064 th most common 86,064 th most common dP 2.6 2.7 2.6 Head fraction analysis,% molar: Ethylene 0.052 0.052 0.068 Propylene 86,379 th most common 85,583 th most common 87,355 th most common Propane 12,041 th most common 12,353 th most common 10,687 th most common Methylacetylene 0.000 0.000 0.212 Propadien 0.000 0.000 0.470 Cyclo-C ₃ 0.044 0.051 0.043 Isobutane 0.000 0.000 0.000 Isobutene 0.007 0.012 0.009 1-Butene 0.781 0.856 O ', 394 n-Butene 0.105 0.151 0.077 trans-2-butene 0.466 0.600 0.116 Vinylacetylene 0.000 0.000 0.000 cis-2-butene 0.155 0.237 0.031 C5 and heavier 0.000 0.000 0.000 % MAPD 0.000 0.000 0.682

Table IIΓ - continued

Current introduction time, h 336 Overpressure, kPa 1924 Distillation temperature residues, ° C 60 Handle: Dosed amount Xkg./h) ... .. (. Liquid .____________ _____. „4 _ ,. 99 ^ __ Dosed hydrogen SCF / h (gas) 10.0 Hydrogen / acetylene ratio 2,002 th most common MA + PD in batch,% mol. 3,690 th most common ^C 3 ^_ 82.3740 C ₃ ^_ + MA + PD 86,064 th most common dP 2.6 Head fraction analysis,% molar: Ethylene 0.069 Propylene 87,421 th most common Propane 10,957 th most common Methylacetylene 0.013 Propadien 0.064 Cyclo-C ₃ 0.045 Isobutane 0.000 Isobutene 0.085 1-Butene 0.739 n-Butene 0.076 trans-2-butene 0.292 Vinylacetylene 0.000 cis-2-butene 0.056 C ₅ and heavier 0.000 % MAPD 0.077

Example 2

The catalyst is a catalyst containing 0.34% by weight of palladium on alumina beads having a particle size of 2.311 to 3.961 mm, available from United Catalysts Inc., under the designation G68C. The usual physical and chemical properties of the catalyst, as provided by the manufacturer, are given below.

Table IV

Designation G68C '

Ball form

Nominal size 5x8 mesh (2,311 x 3,581 mm)

Palladium,% by weight 0.3 (0.27 to 0.33)

Highly porous alumina support

The catalyst is believed to be palladium hydride, which is formed during the reaction. The amount of hydrogen fed to the reactor must be sufficient to keep the catalyst in active form because hydrogen is lost from the catalyst by hydrogenation. An effective amount of hydrogen, as used herein with respect to compounds having 5 carbon atoms, is at least 1.0 to 1.0, preferably above 2.0 to 1.0, for example about 10: 1, expressed as moles of hydrogen per mol of diolefin.

A steel column 310 with a diameter of 76 mm and a height of 914 cm with a reboiler 340, a condenser 320, a reflux system 330 and a flow tube 306 is used, as shown in Fig. 4. The catalyst distillation structure 312 is charged to the middle 457 cm of the column. This structure comprises a catalyst containing 0.34% by weight of palladium on 3.2 mm alumina spheres, which is contained in glass fiber strip boxes and twisted with a stainless steel wire mesh. The column is purged with nitrogen and pressurized to a pressure ⁼ 137 'kPa'; ^The introduced light naphtha, which has been pre-fractionated to remove most of the compounds with 6 or more carbon atoms, is introduced via line 301 at a rate of 22.7 kg / h. When the specified level in the reboiler is reached and the liquid is at the desired level in the column, distillation residues are removed by flow line 308 and feed line 304 and flow line 313 begins to circulate through reboiler 340. Heat is supplied to heater 340 until shows the steam at the top of the column, as can be seen from a uniform temperature of 54 DEG C. through the column, with the addition of hydrogen starting to the column reboiler through the feed line 302 at 8 to 10 SCFH. The pressure in the column is then controlled so as to maintain the temperature of the distillation residues at about 160 ° C and the temperature of the catalyst bed at about 127 ° C. The overpressure of the overhead fraction is then maintained at approximately 1374 kPa. The overhead fraction is collected via flow line 303 and partially condensed in condenser 320, with all condensable components trapped in reflux boiler 330 and returned to the top of the column as reflux through flow tube 306. Non-condensable compounds are vented from reflux boiler 330 through flow tube 307. Liquid the distillation residues are fed through a flow line 308. The results are shown in Table V below, where the batch and the analysis of the composition of the distillation residues are compared.

Table V

Component,% wt. Handle Distillation residues produced % change Light components 0.073 0.000 -100 Dimethyl ether 0.003 0.002 -36 Isobutane 0.488 0.093 -81 Methanol 0.058 0.000 -100 Other compounds • with 4 carbon atoms 4,573 th most common 3,304 th most common -28 3-Methyl-1-butene 1,026 th most common 0.270 -74

Table V - continued

Component,% wt. Handle Produced distillates % Isopentane 31,974 th most common hungry residues 32,066 th most common change 0 1-Pentene 2,708 th most common 0.962 -64 2-Methyl-1-butene 6,496 th most common 4,012 th most common -38 n-Pentane 3,848 th most common 4,061 th most common 6 2-Methyl-1,3-buta- dien 0.147 0.002 -99 trans-2-pentene 6,995 th most common 9,066 th most common 30 Unknown 1 0.138 0.094 -32 cis-2-pentene 3,886 th most common 3,723 th most common -4 2-methyl-2-butene, 11,631 th most common 14,083 th most common 21 trans-piperylene 0.142 0.002 -98 cis-piperylene 0.095 0.003 -97 cyclo-C ₅ 0.001 0.058 -47 c ^{+ e} 6 25,603 th most common 28,198 th most common 10 Total · · < 100,000 100,000

Example 3

During the experiment of Example 2, the pressure in the overhead fraction was adjusted by changing the temperature of the catalyst bed. At lower temperatures, the conversion of diolefins is lower, but the main difference is that the isomerization of 3-methyl-1-butene proceeds much more strongly. Table VI below compares the conversions of diolefins and 3-methyl-1-butene achieved with operating temperatures.

Mean Overpressure Time to Conversion,% molar temperature OH STM isoprene t-pip c-pip 3-methyl-1-butene ° C kPa h

110 893 200 65 57 65 17 121 996 300 97 95 95 55 129 1374 600 100 99 99 80

Example 4

Streams containing compounds with 4 carbon atoms

This set of experiments demonstrates the unexpected removal of dlen from streams of compounds containing 4 carbon atoms at extremely low hydrogen partial pressures. It is also shown that lower overall pressures are equally suitable. The experiments are performed in two ways. In one embodiment, conventional distillation uses a continuous vapor phase. In the second embodiment, a continuous liquid phase of LPC is preferably used.

The reactor used for Experiment 1 is a 76 mm diameter column containing 610 cm of catalyst packing containing 28.3 dm ^{3 of} catalyst material containing 0.5% palladium on alumina with a particle size of 2.311 to 2.641 mm (alumina-E144SDU , Calcinat, Catalyst and Performance Chemicals Division, Mallinckrodt, Inc., with pallet steel rings 15.8 mm in diameter and 137 cm long above the catalyst bed and steel cover rings 15.8 mm in diameter and 472 cm in length catalyst bed.

Experiment 2 uses a 76 mm diameter column containing 610 cm of catalyst packing, containing 28.3 dm ^{3 of} catalyst material, containing 0.5% palladium on alumina with a particle size of 2.311 to 2.641 mm (alumina-E144SDU, product Calcinat, Catalyst and Performance Chemicals Division, Mallinckrodt, Inc.) with 15.8 mm diameter and 137 cm long cover steel rings and 762 cm long demister wire above the catalyst bed and 15.8 mm diameter cover steel rings mm and a length of 1524 cm below the catalyst bed. The catalyst is filled into tubular rings with 25.4 mm of wire provided with a blade placed diagonally on the demisting wire and rolled into packages with a diameter of approximately 76 mm.

The hydrocarbon is fed to the column under the catalyst. At the beginning, the overpressure of the overhead fraction is adjusted to 824 kPa and a hydrocarbon feed is fed to the boiler at a rate of approximately 9 kg per hour, with 10% of the feed being retained in the boiler for 15 minutes, after which time the dosing rate is adjusted to: to retain 50 to 75% of the amount until the temperature of the overhead fraction differs by 11 ° C from the temperature in the reboiler and then the hydrocarbon feed rate is increased to 45 kg / h. When the pressure difference reaches 6.7 kPa, a hydrogen flow of 15 SCFH is started. The boiler is heated to a uniform temperature of 54 ° C and then started; . medium reflux. The overhead pressure is selected and the reaction mixture is distilled. The hydrocarbon feed with 4 carbon atoms and the results for each experiment are given in Tables VII and VIII.

Experiments performed in the LPC process lead to the removal of all dienes, while the usual distillation leaves them *

in quantities of several parts per million under the same conditions.

♦

The range of internal reflux is given as the ratio of liquid immediately below the catalyst charge to distillate (L / D). The data show that the LPC method provides better diene removal.

__ Table VII, _ _{= =} .._________ _________

Example 4, Experiment 1, Part 1 Hours of operation: 41

Conditions:

Hydrogen partial pressure, abs. kPa 16 Handle source FCC from refinery Dosing speed , kg / h 45 Amount of hydrogen, SCFH 15 Overpressure, kPa 824 Distillate, kg / h 42 Internal reflux ratio 0.73. Way ordinary Results: Analysis Handle Head . Distillation Industry faction residues wound % wt. % wt. % wt. % wt. Ethylene 0.02 0.01 0.00 0.00 Ethan 0.20 0.01 0.00 0.69 Propylene 0.27 0.22 0.00 2.61 Propane 0.48 0.44 0.00 3.34 Isobutane 31.38 32.63 0.18 31.70 Isobutene 14.21 : 14,77 0.74 11.41 1-Butene 12.82 4.59 1.07 3.25 1,3-Butadiene 0.2788 0.0030 0.0199 0.0000 n-Butane 9.37 10.13 8.55 4.95 trans-2-butene 17.13 24.69 25.56 11.49 ♦ .2,2-Dimethylpropane 0.00 0.00 0.08 Methylcyclopropane 0.02 0.02 0.02 cis-2-butene 12.50 . 12.20 53.01 4.91 ^c 5 1.26 0.27 10.58 0.06 Heavy compounds 0.01 0.01 0.18 0.21 A total of 100.00 100.0 100.0

kg / h 45.3 42 , 1 2.3 Temperature, ° C 155 188 Summary of components: Component Handle, % wt. Product,% wt Dieny 0.28 30 ppm Isobutane 31.4 31.0 n-Butenes 42.5 43.0 n-Butane 9.4 10.0

% Of 1-butene from total n-butenes 30.2 10.2

Example 4, Experiment 1, Part 2 Hours of operation: 102

Conditions:

Hydrogen partial pressure, abs. kPa 10

Source of FCC refinery feed

Dosing rate, kg / h Amount of hydrogen, SCFH ' 45 10 Overpressure, kPa 824 Distillate, kg / h 42 Internal reflux ratio 0.74 Way LPC Results: Analysis Handle Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. Ethylene 0.02 0.01 0.00 0.00> Ethan 0.20 0.02 0.00 0.70 Propylene 0.27 0.25 0.00 2.13 Propane 0.48 0.47 0.00 2.52 Isobutane 31.38 32.97 0.21 23.22 Isobutene 14.21 14.82 0.81 .8,18 1-Butene 12.82 3.67 1.15 1.92 1,3-Butadiene 0.2788 0.0000 0.0211 0.0000 n-Butane 9.37 9.93 8.84 3.43 trans-2-butene 17.13 25.37 25.71 8.29 2,2-Dimethylpropane 0.00 0.00 0.08 Methylcyclopropane 0.02 0.02 0.02 cis-2-butene 12.50 12.20 52.25 3.46 ^C 5 1.26 0.28 10.70 0.00 Heavy compounds 0.01 0.00 0.20 0.00 Total 100.00 100.0 100.00

kg / h 45.4 42.2 2.3 Temperature, ° C 155 188 Summary of components: Component Handle,% wt. Product,% mass Dieny 0.28 0 ppm Isobutane 31.4 31.2 n-Butenes 42.5 42.6 n-Butane 9.4 9.8 % 1-butene z of total n-butenes 30.2 8.2

. ΠΊ —- 1—. * 4 Ί-If -> T7T T „V». Λ Xř V * τ »A Λ1.Τ 'Λ« .Ί _., - ______ ... _ „

- ± C1JJU-LA.CI ViJ. - WVV V WJii —-Γ-- - - -

Example 4, Experiment 1, Part 3 Hours of operation: 161

Conditions:

Hydrogen partial pressure, abs. kPa '5.5

Source of FCC refinery feed

Dosing rate, kg / h 45.4

Amount of hydrogen, SCFH 5

Overpressure, kPa 824 Distillate, kg / h 42 Internal reflux ratio .0.74- Way ordinary Results: Analysis Handle Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. Ethylene 0.02 0.01 0.00 0.00 Ethan 0.20 0.01 0.00 0.64 Propylene 0.27 0.25 0.00 1.96 Propane 0.48 0.46 0.00 2.24 Isobutane .31.38 -32.84 0.47 20.08 Isobutene 14.21 14.87 0.87 7.12 1-Butene 12.82 10.32 1.20 4.26 1,3-Butadiene 0.2788 0.0262 0.0227 0.0000 n-Butane 9.37 9.52 8.71 2.87 trans-2-butene 17.18 19.35 25.66 5.71 2,2-Dimethylpropane 0.00 0.00 0.08 Methylcyclopropane 0.02 0.02 0.02 cis-2-butene 12.50 12.08 52.60 2.96 ^c 5 1.26 0.24 10.23 0.00 Heavy compounds 0.01 0.00 0.12 0.00 Total 100.00 100.0 100.00

kg / h 45.4 42.0 2.3 Temperature, ° C 155 188 Summary of components: Component Handle,% mass Product,% mass Dieny 0.28 262 ppm Isobutane 31.4 30.9 n-Butenes 42.5 43.0 n-Butane 9.4 9.3 % 1-butene z of total n-butenes 30.2 22.6

Table. VII ₌ ^ _=: continued.

Example 4, Experiment 1, Part 4 Hours of operation: 188

Conditions: Hydrogen partial pressure, abs. kPa 10 Handle source FCC from refinery Dosage amount, kg / h 45.4 Amount of hydrogen, SCFH 10 Overpressure, kPa 824 Distillate, kg / h 42 Internal reflux ratio 0.74 Way < ordinary Results: Analysis Handle Head Distillation Industry faction residues wound % wt. % wt. % wt. % .wt. Ethylene 0.02 0.01 0.00. 0.00 Ethan 0.20 0.01 0.02 0.64 Propylene 0.27 0.25 0.03 2.08 Propane 0.48 0.46 0.05 2.42 Isobutane 31.38 32.97 3.92 20.74 Isobutene 14.21 14.90 2.43 7.27 1-Butene 12.82 7.29 2.61 3.26 1,3-Butadiene 0.2788 0.0105 0.0509 0.0000 n-Butane 9.37 9.64 8.81 2.90 trans-2-butene 17.13 21.91 24 ^ 64 6.32 2,2-Dimethylpropane 0.00 0.00 0.07 Methylcyclopropane 0.02 0.02 0.02 cis-2-butene 12.50 12.29 47.97 2.97 ^C 5 1.26 0.23 9.22 0.00 Heavy compounds 0.01 0.01 0.17 0.00 Total 100.00 100.0. 100.00

kg / h 45.3 42.2

Temperature, ° C 155

Summary of components:

2.3 1.0

188 wt.

Component Handle,% wt. Product, Dieny 0.28 105 ppm Isobutane 31.4 31.3 n-Butenes 42.5 42.6 n-Butane 9.4 9.5

% Of 1-butene from total n-butenes 30.2 16.4 ^ Table - ^ / 1-11 -..-., =:, - ^, == = .. =, -.

Example 4, Experiment 2 Hours of use: 138 Part 1 Conditions: Hydrogen partial pressure, abs. kPa 10 Handle source FCC from refinery Dosage amount, kg / h 25.4

Amount of hydrogen, SCFH 15

Overpressure, kPa 859 Distillate, kg / h 17 Internal reflux ratio 4.72 Way LPC Results: Analysis Handle Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. Ethylene 0.03 0.03 0.00 0.00 Ethan 0.22 0.11 0.00 0.14 Propylene 0.24 0.31 0.00 '0.68 Propane 0.53 0.68 0.00 1.18 Isobutane 28.17 39.45 0.01 33.16 Isobutene 15.05 21.03 0.0032 16.91 1-Butene 13.91 7.81 0.01 5.99 1,3-Butadiene 0.3441 0.0000 0.0000 0.0000 n-Butane 8.65 7.34 12.86 5.04 trans-2-butene 17.76 16.71 40.71 11.43 2,2-Dimethylpropane 0.00 0.00 0.04 Methylcyclopropane 0.02 0.01 0.03 cis-2-butene 13.55 6.51 40.84 4.26 ^C 5 1.53 0.02 .5.47 0.00 Heavy compounds 0.00 0.00 0.01 0.05 Total 100.00 100.0 100.00

kg / h 25.3 16.8 6.8 Temperature, ° C 164 182 Summary of components: Component Handle, % wt. Product,% mass Dieny 0.3 0 ppm Isobutane 28.2 28.5 n-Butenes 45.2 43.9 n-Butane 8.7 8.7

% Of 1-butene from total n-butenes 30.8 12.8. —Ta.Van.l ka—VT.TJ .- = ._ nnkKar: nvá.nj ____. .... ____ j ........ „„

Example 4, Experiment 2, Part 2 Hours of operation: 173

Conditions:

Hydrogen partial pressure, abs. kPa 10

Source ^Refinery FCC feed

Dosage rate, kg / h 25.3

Amount of hydrogen, SCFH 15

Overpressure, kPa 859 Distillate, kg / h 14.5 Internal reflux ratio 5.46 . Way LPC Results: Analysis Handle Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. Ethylene 0.03 0.03 0.00 0.02 Ethan .0.22 0.09 0.00 0.29 Propylene 0.24 0.33 0.00 0.77 Propane . 0.53 0.74 0.00 _F 2.56 Isobutane 28.17 43.97 0.01 43.60 Isobutene 15.05 23.39 0.0541 5.45 1-Butene 13.91 7.20 0.22 19.75 1,3-Butadiene 0.3441 0.0000 0.0024 0.0000 n-Butane 8.65 5-, 24 15.64 3.88 trans-2-butene 17.76 13.92 42.32 8.80 2,2-Dimethylpropane 0.00 0.00 0.03 Methylcyclopropane 0.02 0.01. 0.03 cis-2-butene 13.55 5.07 37.33 3.22 ^C 5 1.53 0.00 4.35 '0.00 Heavy compounds 0.00 0.00 0.01 0.00 Total 100.00 100.0 100.00

kg / h 25.4 14 6 8.6 Temperature, ° C 164 182 Summary of components: Component Handle,% wt. Product,% mass Dieny Isobutane 0.3 28.2 0 ppm 29.1 - and', n-Butenes n-Butane 45.2 8.7 44.9 8.6 % 1-butene z total n-butenes 30.8 * 13.3

ι

Τ '»- Τ - 1 ____ Ί **

ΠIXldU “□

Streams containing light FCC diesel

The same methods as in Example 4 were used, except that the catalyst was G68C-1, containing 0.4% palladium on alumina with a particle size of 1.397 to 2.641 mm, a product of United Catalyst, Inc. A 914 cm (42.5 dm ³⁾ catalyst bed packed as a distillation structure as described in Example 4 was placed on a 76 mm diameter column with 15.8 mm diameter and 152 cm long steel ring rings. 304 cm of open space above and 91 cm of defogging wire and 1520 cm of cover rings below. Distillation is performed by hydrotreating. compounds with 5 carbon atoms such as. overheads and heavier components such as distillation residues. The batches, operating conditions and results for each of the three experiments are given in Tables IX to XI.

The results of Experiment 3 in 74 hours of operation, which are performed at a low hydrogen partial pressure and a mass hourly space velocity of 20, are below the expected level. Increasing the absolute partial pressure of hydrogen to only 30 kPa in 27.2 hours of operation in the usual distillation process improves the removal of the diene tenfold.

___and.

fc

Table IX

Example 5, Experiment 1 Hours of operation: 99

Conditions:

Hydrogen partial pressure, abs. kPa 31 Dosage amount, kg / h 99.3 Amount of hydrogen, SCFH 20 Overpressure, kPa 859 Distillate, kg / h 21.3 Internal reflux ratio 2.11 Way LPC Results: Analysis Handle Head Distillation faction wound remnants % wt. % wt. % wt. % wt ^C 4 0.00 0.00 0.00 Isobutane 0.00 0.02 0.00 0.02 · Other C ₄ 0.33 1.52 0.04 3-Methyl-1-butene 0.26 0.27. 0.06 y Isopentane 7.40 3 2.40 2.32 33.23 1-Pentene 1.07 1.47 0.34 2-Methyl-1-butene 1.81 4.09 0.60 n-Pentane 3.82 17.65 1.62 2-Methyl-1,3-butadieneO, 1761 0.0000 0.0595 trans-2-pentene 2.45 14.99 1.02 Unknown 1 0.02 0.04 0.02 cis-2-pentene 1.36 4.86 0.59 21.62 2-Methyl-2-butene 3.28 17.93. 1.69 trans-piperylene 0.18 0.00 0.10 cis-piperylene 0.06 0.00 0.04 Cyclopentene 0.29 0.26 0.26 Unknown 2 5.12 4.12 11.26

Heavy compounds 72.36 0.38 79.97 Total 100.00 100.0 100.00 kg / h 99.2 21.3 78.0 0.00 Temperature, ° C 124 213

Summary of components:

Component Handle,% wt. Product,% wt. Dieny ^- ' ——--- _ ™. —'Eg-ρρπ; 2MB1 + 2MB2 22.9 24.2 Isopentane 33.4 32.5 Pentenes 22.0 22.6 n-Pentane 17.2 18.8

% 3-MB-1 from total isoamylenes 5.23% l-pentene from total n-pentenes 22.0

1.63

9.5 i

Table X

Example 5, Experiment 2, page 1 Hours of operation: 45

Conditions.

Hydrogen partial pressure, abs. kPa 33 Dosed amount , kg / h 98.4 Amount of hydrogen, SCFH 20 Overpressure, kPa 859 Distillate, kg / h 19.0 Internal reflux ratio 2.22 Way LPC Results: Analysis Handle Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. ^C 4 0.00 0.00 0.00 Isobutane 0.03 0.16 0.00 0/3 2 Other C ₄ 1.46 7.33 0.00 3-Methyl-1-butene 0.21 0.20 0.00 Isopentane 7.85 38.92 0.08 34.49 1-Pentene 0.76 1.04 0.02 2-Methyl-1-butene 1.37 3.08 0.06 n-Pentane 3.56 13.79 0.73 2-Methyl-1,3-butadieneO, 101 0.000 0.0110 trans-2-pentene 2.08 10.77 0.4 2 Unknown 1 0.02 0.04 0.01 cis-2-pentene 1.15 3.50 0.29 16.97 2-Methyl-2-butene 2.87 13.90 0.91 trans-piperylene 0.11 0.00 0.04 cis-piperylene 0.04 0.00 0.01 Cyclopentene 0.31 0.43 0.23 Unknown 2 6.49 6.01 6.46

Heavy compounds Total 71.58 100.00 0.83 100.00 90.71 100.00 kg / h 98.5 19.0 79.5 0.00 Temperature, ° C 127 208 Summary of components:

Component Handle,% wt. Product,% wt.

Daily '- ’' ——- 1721 - --------- O-ppm—-

2MB1 + 2MB2 20.8 21.6 Isopentane 38.4 40.3 .Penteny 19.6 18.9 n-Pentane 17.4 17.3

% 3-MB-1 from total isoamylenes 4.80 0.94% 1-pentene from total n-pentenes 19.0 6 _ø l

Table X - continued

Example 5, Experiment 2, page 2 Hours of operation: 201

Conditions:

Hydrogen partial pressure, abs. kPa 20 Dosing rate, kg / h 99.3 Amount of hydrogen, SCFH 20 Overpressure, kPa 515 Distillate, kg / h 18.6 Internal reflux ratio 2.50 Way LPC results: Handle Analysis Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. ^C 4 0.00 0.02 0.00 Isobutane 0.03 0.15 0.00 0.30 Other C ₄ 1.48 6.85 0.00 3-Methyl-1-butene 0.21 0.32 0.00 Isopentane 7.85 36.28 0.03 42.53 1-Pentene 0.76 1.18 0.01 2-Methyl-1-butene 1.37 3.94 0.04 n-Pentane 3.56 15.98 0.58 2-Methyl-1,3-butadiene 0.1013 0.0000 0.0085 trans-2-pentene 2.08 12.08 0.3 3 Unknown 1 0.02 0.05 0.00 cis-2-pentene 1.15 3.88 0.23 18.14 2-Methyl-2-butene 2.87 13.81 0.76 trans-piperylene 0.11 0.00 0/04 cis-piperylene 0.04 0.00 0.01 Cyclopentene 0.31 0.42 0.20 Unknown 2 6.49 4.49 6.35

Heavy compounds 71.58 0.54 91.42 Total 100.00 100; oo 100.00 kg / h 99.3 18.6 79.7 1.2 Temperature, ° C 100 182

Summary of components:

Component Handle,% wt. Product,% wt.

Drives 1.21 ^ř u ppm 2MB1 + 2MB2 20.8 20.9 Isopentane 38.4 38.6 Pentenes 19.6 20.5 n-Pentane 17.4 r , 18.2 % 3-MB-1 z total isoamylenes 4.80 1.50 % 1-pentene z total n-pentenes 19.0 6.0

Table XI

Example 5, Experiment 3, page 1 Hours of operation: 44

Conditions:

Hydrogen partial pressure, abs. kPa 19 Dosing rate, kg / h 133.7 Amount of hydrogen, SCFH 20 Overpressure, kPa 687 Distillate, kg / h 24.9 Internal reflux ratio 2.65 Way LPC Results: Handle Analysis Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. ^C 4 0.02 0.07 0.00 Isobutane 0.07 0.27 0.00 0.49 Other C ₄ 1.41 0.00 0.00 3-Methyl-1-butene 0.25 0.73 0.00 Isopentane 8.66 36.35 0.20 26.57 1-Pentene 0.87 2.09 0.02 2-Methyl-1-butene 1.83 6.60 0.05 n-Pentane 1.51 6.42 0.12 2-Methyl-1,3-butadiene 0.0537 0.0024 0.0000 trans-2-pentene 2.58 13.00 0.21 Unknown 1 0.03 0.07 0.02 cis-2-pentene 1.42 5.13 0.22 28.45 2-Methyl-2-butene 3.93 15.45 1.12 trans-piperylene 0.06 0.00 0.02 cis-piperylene 0.03 0.00 0.01 Cyclopentene 0.06 0.05 0.04 Unknown 2 7.50 6.65 7.69

Heavy compounds 69.71 7.12 90.28 Total 100.00 100.00 100.00 kg / h. 133.2 24.9 107.4 Temperature, ° C 116 198 Summary of components: Component Handle,% wt. Product,% wt. Dieny 0.68 2MB1 + 2MB2 27.1 27.7 Isopentane 40.7 39.7 Pentenes 22.9 24.4 n-Pentane 7.1 7.1.

% 3-MB-1 from total isoamylenes 4.23 2.61% 1-pentene from total n-pentenes 17.8 9.2

Table XI - continued

Example 5, experiment 3, page 2 Hours of operation: 74

Conditions:

Hydrogen partial pressure, abs. kPa 10 Dosing rate, kg / h 133.8 Amount of hydrogen, SCFH 10 Overpressure, kPa 687 Distillate, kg / h 23.6 Internal reflux ratio 2.65 Way LPC Results: Handle Analysis Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt. ^C 4 0.02 0.08 0.00 Isobutane 0.07 0.29 0.00 0.68 Other C ₄ 1.41 6.44 0.00 3-Methyl-1-butene 0.25 1.13 0.00 Isopentane 8.66 39.14 0.20 32.86 1-Pentene 0.87 3.65 0.02 2-Methyl-1-butene 1.83 8.35 0.05 n-Pentane 1.51 5.84 0.12 2-Methyl-1,3-butadiene 0.0537 0.0417 0.0000 trans-2-pentene 2.58 10.45 0.21 Unknown 1 0.03 0.07 0.02 cis-2-pentene 1.42 5.11 0.22 0.00 2-Methyl-2-butene 3.93 13.09 1.12 and trans-piperylene 0.06 0.03 0.02 cis-piperylene 0.03 0.05 0.01 Cyclopentene 0.06 0.06 0.04 Unknown 2 7.50 5.29 7.69

Heavy compounds 69.71 0.90 90.28 Total 100.00 100.00 100.00 kg / h 88.5 23.6 109.4 Temperature, ° C 113 195 Summary of components: Component Handle,% mass Product, % wt.

0.9

Dleny ' Q -, ’6-8 -------— —-1263-ppm ~ 2MB1 + 2MB2 27.1 27.5 Isopentane 40.7 42.4 Pentenes 22.9 21.9 n-Pentane 7.1 6.5 % 3-MB-1 z total isoamylenes 4.23 4.02 % l-pentene z total n-pentenes 17.8 17.6

Table XI - continued

Example 5, Experiment 3, page 3 Hours of operation: 272

Λ

Conditions:

Hydrogen partial pressure, abs. kPa 30 Dosed amount , kg / h 133.8 Amount of hydrogen, SCFH 30 Overpressure, kPa 687 Distillate, kg / h 24.0 Internal reflux ratio 2.43 Way ordinary Results: Analysis Handle Head Distillation Industry faction residues wound % wt. % wt. % wt. % wt ^C 4 0.02 0.08 0.00 Isobutane 0.07 . 1.03 0.00 l ', 58' Other C ₄ 1.41 11.21 0.00 3-Methyl-1-butene 0.25 0.91 0.00 Isopentane 8.66 42.05 0.60 26.14 1-Pentene 0.87 2.11 0.14 2-Methyl-1-butene 1.83 6.24 0.36 n-Pentane 1.51 5.06 0.63 l_ 2-Methyl-1,3-butadieneO, 0537 0.0057 0.0000 trans-2-pentene 2.58 9.32 0.98 Unknown l 0.03 0.06 0.02 cis-2-pentene 1.42 3.98 0.60 18.29 2-Methyl-2-butene 3.93 11.56 1.87 trans-piperylene 0.06 0.00 0.03 cis-piperylene 0.03 0.01 0.01 Cyclopentene 0.06 0.04 0.04 Unknown 2 7.50 5.29 13.06

1C6A.C OlUUUCiliny ........, x * .r \ -ti__ __ <1. _____ ±, ± X - ______ Λ Ί. Z * I ^- ___ --- '01, 03 ----- Total 100.00 100.00 100.00 kg / h 133.8 24.0 108.0 1.81 Temperature, ° C 112 187

Summary of components:

Component Handle,% wt. Product,% wt.

Dieny 0.68 126 ppm 2MB1 + 2MB2 27.1 25.7 Isopentane 40.7 43.1 Pentenes 22.9 22.6 n-Pentane 7.1 - 7.3

% 3-MB-1 from total isoamylenes 4.23 3.17% 1-pentene from total n-pentenes 17.8 11.2

56 · Example 6

Streams containing compounds with 3 carbon atoms

The same procedure as in Example 4 was used, except that the catalyst in Experiment 1 was a G68C catalyst containing 0.3% palladium and alumina having a particle size of 2.971 to 3.961 mm, a product of United Catalyst, Inc. 604 cm of catalyst charge (28.3 dm ^{3 of} catalyst material), prepared as a distillation structure as described in U.S. Patent No. 5,266,546, which forms a tubular wire mesh approximately 50.8 mm long and 50.8 mm in diameter, which is firmly connected to each other at an angle of 90 °. The catalyst packing is introduced into a column 76 mm in diameter, equipped with cover steel rings 15.8 mm in diameter and 152 cm and 304 cm in length of open space above and 91 cm of defogging wire and 1520 cm with cover rings 15.8 mm in diameter. The same structure and column were used in Experiment 2, except that the catalyst was a G68H catalyst containing 0.3% palladium and 0.3% silver on alumina, manufactured by United Catalyst, Inc.

Distillation is carried out by removing the hydrotreated compound having 5 carbon atoms as the overhead fraction and the heavier components as distillation residues. The batches, operating conditions, and results for each of the three experiments are shown in Tables XII and XIII.

-. - .. Table 'XII ...... ₌ ,.

Example 6, Experiment 1 Hours of operation: 213

Conditions:

Hydrogen partial pressure, abs. Dosed amount, kg / h Amount of hydrogen, SCFH Overpressure, kPa

Distillate, kg / h Internal ratio reflux Way Results: Analysis Handle Methane % wt 0.00 Ethylene 0.00 Ethan 0.05 Prop 85.43 Propane 9.93 Methylacetylene 1.99 Propadien 0.81 Cyclopropane 0.05 Isobutane 0.00 Isobutene 0.01 1-Butene 0.21 Butadiene 1.37 n-Butane 0.00 Vinylacetylene 0.00 trans-2-butene 0.01 cis-2-butene 0.01 ^C 5 0.04

kPa 44

40.8

1718 - ............... 3772 ’

0.88

LPC

Head Distillation faction residues % wt. % wt. 0.00 0.00 0.00 0.00 0., 03 0.00 88.88 22.85 11.02 8.81 0.0000 - 7.66 0.0000 5.45 0.04 0.34 0.00 0.10 0.00 0.27 0.00 6.30 0.00 25.59 0.00 2.56 0.00 0.22 0.00 2.34 0.00 1.12 0.00 0.75

Ventilation% wt.

0.06

0.45

78.94

7.20

0.13

0.04

- 58 - ^C 6 0.00 0.00 13.51 Heavy compounds 0.00 0.00 0.01 0.05 Total 100.00 100.00 100.00 kg / h ' 25.4 16.8 6.8 1.9 Temperature, ° C 45 102 Summary of components: Component Handle,% mass Product,% wt. Dieny 4, 2 0 ppm Propylene 85, 4 65.8 Propane ’9, 9 10.8 ^C 6 O, 06 0.65

Example 6, Experiment 2 Hours of operation: 152

Conditions:

Hydrogen partial pressure, abs. Dosage, kg / h Hydrogen, SCFH Overpressure, kPa

Distillate, kg / h

Internal reflux ratio Method

Results:

Analysis Handle Methane % wt 0.00 Ethylene 0.00 Ethan 0.05 Prop 85.43 Propane 9.93 Methylacetylene 1.99 Propadien 0.81 Cyclopropane 0.05 Isobutane 0.00 Isobutene 0.01 1-Butene 0.21 Butadiene 1.37 n-Butane 0.00 Vinylacetylene 0.00 trans-2-butene 0.01 cis-2-butene 0.01 ^C 5 0.04

40.8

1718 '387 Γ 1.27 LPC

Head Distillation Industry faction residues wound % wt. % wt. %. mass 0.00 0.00 0.01 0.00 0.00 0.54 0.03 0.00 88.94 22.17 74.14 10.12 12.13 6.47 0.0000 8.70 0.0000 5.90 0.03 0.43 0.00 0.39 0.00 0.34 0.00 6.08 0.13 0.00 30.57 0.00 3.02 0.00 0.25 0.00 0.70 0.00 0.22 0.00 0.83 0.04

^C 6 0.00 0.00 8.76 Heavy compounds 0.05 0.02 1.52 Total 100.00 100.0 100.00 kg / h 40.8 38.0 1.6 Temperature, ° C 45 77 Summary of components: Component Handle,% mass Product,% wt Dieny 4, 2 0 ppm Propylene 85, 4 86.1 Propane 9, 9 10.0 ^C 6 O, 06 0.42

IV (VIJ -y # í -—-- F _; JAlDíi \ H ·. QHjAfnsAí / igyd avy o ^!

Claims (45)

PATENT CLAIMS 96 lýAjz 01500 T> 0 1. A process for the selective hydrogenation of highly unsaturated]] g ^of compound j, characterized in that it comprises feeding the hydrocarbon stream containing highly unsaturated compounds which comprise diolefins and acetylenes along with a hydrogen stream in the effective absolute hydrogen partial pressure of at least about 687 Pa to less than 481 kPa to a distillation column reactor ₍ containing a hydrogenation catalyst which is a component of the distillation structure) and selectively hydrogenating a portion of the highly unsaturated compounds. 2) a second hydrogen-containing stream into the feed zone of the distillation column reactor; (b) simultaneous operation in this distillation column reactor at a partial hydrogen pressure of from about 1 mmHg to less than 50 mmHg i) contacting these streams in a distillation reaction zone with a hydrogenation catalyst prepared in a form that acts as a distillation structure, reacting substantially all diolefins and acetylene compounds with hydrogen to form less unsaturated hydrocarbons in the reaction mixture; and ii) separating the olefins contained in this first stream and any olefins formed by hydrogenation from the reaction mixture by fractional distillation. ' 2. The process of claim 1 wherein the hydrocarbon stream comprises aliphatic compounds having from 3 to 9 carbon atoms. The process according to claim 1, wherein the hydrocarbon stream comprises a major amount of normal olefins that are obtained as hydrogenation products. The method of claim 1, wherein the hydrocarbon has a WHSV in the range of 0.1 to 35. The method of claim 2, wherein the overhead pressure is in the range of 0 to 2405 kPa. 6. The method according to claim 1, characterized in that the hydrogen partial pressure is less _(than 344 kPa. The method of claim 6, wherein the absolute partial pressure of hydrogen is less than 69 kPa. The method of claim 7, wherein the absolute partial pressure of hydrogen is less than 48 kPa. The method of claim 5, wherein the absolute partial pressure of hydrogen is less than 344 kPa. The method of claim 9, wherein the absolute partial pressure of hydrogen is less than 69 kPa. 11. The process of claim 10 wherein the absolute partial pressure of hydrogen is less than about 48 kPa; 12. The process of claim 1 wherein the hydrogenation catalyst comprises a metal from Vlil. or a compound of such a metal as a catalyst component. 13. The process of claim 12 wherein the catalyst comprises palladium. 14. The process of claim 5 wherein the absolute pressure of the overhead fraction is in the range of about 50 psi. 15. A process for the selective hydrogenation of highly unsaturated compounds including diolefins and acetylene compounds contained in an olefin-rich stream, comprising the steps of: (a) introduction. - · · 1 V — Γ * -Ί -1.¼ λ ν \ λ * λ 11 / -3 1.1 / “* η Ví Λ .. Λ.1 .ο F Τ Λ5Λ 7 ΙίΙ-ί.Λ 1 λ € Ί η.ν X-yx VllAllV 'W W - W W W W W W W AH f-y acetylene hydrocarbon compounds and 16. The process of claim 15 wherein the first stream is introduced at or below the lower end of said distillation reaction zone. 17. The process of claim 15 wherein the streams are fed separately to said distillation column reactor. 18. The method of claim 15 wherein the first and second streams are mixed prior to entering said distillation column reactor. 19. The process of claim 15 wherein the hydrocarbon stream comprises aliphatic compounds containing from 3 to 9 carbon atoms. 20. The process of claim 19 wherein the hydrocarbon stream comprises a fraction containing a compound having 3 carbon atoms. 21. The method of claim 19, wherein the hydrocarbon stream comprises a fraction containing a compound having 4 carbon atoms. 22. The method of claim 19, wherein the hydrocarbon stream comprises a fraction containing a compound having 5 carbon atoms. 23. The process of claim 19 wherein the hydrocarbon stream comprises a fraction containing a compound of 6 carbon atoms. 24. The process of claim 19 wherein the first and second streams are combined prior to introduction into the distillation column reactor. 25. The process of claim 15, wherein the hydrogenation catalyst comprises a Group VIII metal or a compound of such a metal as a catalyst component. 26. The process of claim 25 wherein the hydrogenation catalyst comprises from 0.1 to 5.0% by weight of palladium oxide on the alumina extrudate. 27. The process of claim 15, wherein the overpressure in the overhead column of the distillation column reactor is from 1649 to 2164 kPa. 28. The method of claim 27, wherein the first layer comprises an overlap. —'29. 15. The method of claim 15, wherein:. 3. The method of claim 1, wherein the distillation structure comprises a flexible, semi-solid, open tubular wire mesh material which is filled with particles of a hydrogenation catalyst material. 30. The process of claim 15, further comprising the step of (c) removing the separated olefins of step (b) (ii) together with any alkanes, and lighter compounds including any unreacted hydrogen from said distillation column reactor as overhead. 31. The process of claim 15 wherein the distillation column reactor is operated at an overpressure in the overhead of from 0 to 1718 kPa. Ť 32. The method of claim 31, wherein the overpressure is in the range of about 20 to 50 psi. 33. The process of claim 15 wherein the temperature in the distillation reaction zone is in the range of 4 to 149 [deg.] C. 34. The process of claim 33, wherein the temperature in the distillation reaction zone is in the range of 43 to 132 ° C. 35. The process of claim 15 wherein substantially all of the diolefins and acetylene compounds are eliminated from the hydrocarbon stream. 36. The method of claim 15, wherein the first stream has a WHSV in the range of 0.1 to 35. 37. The process of claim 16, wherein the hydrogenation catalyst comprises a metal of Group VIII, a group of periodic elements, or a compound of such a metal as a catalyst component. 38. The process of claim 37 wherein the hydrogenation catalyst comprises from 0.1 to 5.0% by weight of palladium oxide on the alumina extrudate. 39. The process of claim 37, wherein the distillation column reactor is operated at an overpressure in the overhead of from 0 to 1718 kPa. 40. The process of claim 39 wherein the temperature in the distillation reaction zone is in the range of 4 to 149 [deg.] C. 41. The method of claim 40, wherein the overpressure is in the range of about 20 to 50 psi. 42. The process of claim 41, wherein the temperatures in the distillation reaction zone range from 43 to 132 [deg.] C. 43. The method of claim 42, wherein the absolute partial pressure of hydrogen is in the range of about 1 to about 50 psi. 44. The method of claim 43, wherein the internal reflux is in the range of 0.5 to 5 L / D. 45. The process of claim 15 wherein substantially all of the highly unsaturated compounds are dehydrogenated. I -nad! . _____